


Perfect Numbers

by middlemarch



Category: Hidden Figures (2016), Mercy Street (TV)
Genre: Algebra, Alternate Universe, Crossover, Euclid, Female Character of Color, Female Friendship, Gen, Mathematicians, Vignette, number theory
Language: English
Status: Completed
Published: 2017-08-01
Updated: 2017-08-01
Packaged: 2018-12-09 14:06:04
Rating: General Audiences
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 465
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11670603
Author URL: https://archiveofourown.org/users/middlemarch/pseuds/middlemarch
Summary: Other people went for a walk or listened to music. That had never worked for Charlotte.





	Perfect Numbers

**Author's Note:**

  * For [tvsn](https://archiveofourown.org/users/tvsn/gifts).



“What’s that?”

Charlotte started to cover the paper with her palm, could feel the shape her fingers would have to take to crumple it up so that what she had written would not be seen, the movement as instinctive as breathing. She felt the slick weight of the page, better quality than the cheap dime store notebooks she used at home, but not the pencil’s mark as she registered there was no warning to heed, no threat. There was only Katherine and Charlotte saw that the other woman knew what Charlotte had feared, well enough not to make anything of it.

“Oh. It’s you. Don’t see you much anymore,” Charlotte said. She wasn’t jealous, she didn’t think she was, but she wondered what it was like in that big room. What it would feel like to be so close to all those equations. Once, she would have thought mathematics would level them, like a tidal wave could crush a city to rubble and stray timber, but she knew better now. The numbers wouldn’t mind but they needed to be caught or chased or coaxed and it was people who did that. And people liked nothing better than to do the simplest math, greater and less than.

“Well, best to stay busy,” Katherine replied. She was not exactly closed off but Charlotte felt she was waiting for something. “What’re you doing, there?” Katherine gestured to the paper.

“I’m just foolin’ around a little, it helps me relax.” The page was nearly full; the pencil had skimmed across the page almost as fast as her thoughts. There wasn’t a word for the way she was then; joy was not right, not quite, nor reverie or absorption. It might be the feeling a hawk had, lifting its wing to the air, or how the whitewashed inside of the church was painted gold when the choir sang gospel. She thought of ants at a picnic, finding a cherry pie, and how steam rose from the tub when you sank in on a cold night.

“You like number theory, I guess-- there’re some Abelian extensions? There?” Katherine said, pointed more closely, then looking straight at Charlotte, seeking her confirmation and offering her approval. Charlotte nodded, liking both.

“Yes. You prefer geometry, Euclid, right?” Charlotte said. 

“Maybe Euclid prefers me? Seems it’s how my mind’s always worked,” Katherine said with a laugh.

“You relaxed enough for a cup of coffee? Be nice to sit and drink it with someone understanding,” she added. Charlotte felt the numbers around her, them, the way some might sense the Lord or molecules or luck; she knew they’d wait for her.

“That sounds perfect,” Charlotte replied. She saw Katherine took her meaning, smiling at the reference to Euclid, easy with the rarity of finding a peer.

**Author's Note:**

> I have changed it up and made math!Charlotte instead of math!Mary because I initially had the idea of a bigger crossover and then I decided, I didn't want to see Jed or Mary or Emma in the Hidden Figures world but I did want more time with Charlotte and I wanted her to have a friend who was truly her equal.
> 
> Euclid first wrote about perfect numbers in 3000 BC in Alexandria, in his Elements. Succinctly, in number theory, a perfect number is a positive integer that is equal to the sum of its proper positive divisors, that is, the sum of its positive divisors excluding the number itself (also known as its aliquot sum). Equivalently, a perfect number is a number that is half the sum of all of its positive divisors (including itself) i.e. σ1(n) = 2n.


End file.
